Phone makers switch focus to mAh, not millimeters

LG and Huawei are putting 3,000mAh batteries in the their latest smartphones.

With the latest generation of high-end smartphones sporting power-hungry 5-inch screens, a growing number of phone vendors are emphasizing bigger batteries rather than thinner devices.

After HTC's introduction of a 5-inch, full-HD screen on its Droid DNA phone, also know as Butterfly, Sony and Huawei Technologies showed similar products at International CES in Las Vegas and, on Tuesday, LG Electronics expanded its Optimus range with the G Pro.

LG's new smartphone was introduced as part of NTT DoCoMo's spring line-up, and will go on sale in early April in Japan. In addition to a 5-inch screen with a resolution of 1920 pixels by 1080, the Optimus G Pro has a Snapdragon S4 Pro 1.7 GHz quad-core processor and a 13-megapixel camera.

That spec is similar to HTC's Droid DNA, but instead of the DNA's 2,020 milliamp-hour battery, LG has equipped the Optimus G Pro with a 3,000mAh one, the same capacity as Huawei's Ascend D2.

This burgeoning trend is good news for users that prioritize battery life over phone size.

"The decision to put a 3,000mAh battery in the Optimus G Pro was based on our belief that this device deserved a battery that could keep the large 5-inch screen running strong all day. It also sends a clear message to consumers, many of whom say short battery life is their biggest gripe," LG's Ken Hong said via email.

The effect of the bigger battery on the LG phone's size is barely visible: it is approximately 0.4 millimeters thicker than the HTC Droid DNA.

Not all vendors are jumping on the bigger battery band wagon: Sony's Xperia Z, also unveiled at International CES, has a 2,330mAh battery.

However, increasing battery life isn't just about the capacity of the battery. The Xperia Z comes with a new feature called Battery Stamina mode. It improves standby time by automatically shutting down battery-draining apps whenever the screen is off and starting them up again when the screen is back on. The more applications a user has installed, the bigger the effect of the feature, according to Sony. Huawei lowers battery consumption by automatically turning off the transmitter circuit when data transmission is not in use to keep the Ascend D2 going for longer, it said.

The chip vendors are also working to decrease the power consumption of their processors. Nvidia recently launched the Tegra 4, which is based on ARM's Cortex-A15 design. It uses 45 percent less power than the Tegra 3 in common situations, thanks to a second-generation battery saver core and more advanced power management, according to Nvidia.

When it comes to power effiency, the Tegra 4 will compete with processors based on ARM's big.LITTLE processing architecture, which in its first iteration combines the Cortex-A15 with the frugal Cortex-A7 on one die.